An amplification circuit that amplifies an electrical signal have heretofore been used in a light receiving circuit and the like. For example, a feedback circuit is known that feeds back output voltage of an inversion amplifier to the input terminal, a light receiving element being coupled to the input terminal.
However, in the above-described technology in the prior art, in a configuration in which alternating current (AC) coupling is used between the amplification circuit and another circuit, a high pass filter is formed by AC coupling, causing a problem of occurrence of a lower cut-off frequency.
When a lower cut-off frequency occurs, a sag occurs due to attenuation of a low frequency component of a signal. In addition, when a capacitance of a capacitor of AC coupling is increased in order to raise the lower cut-off frequency, the size of the device increases.
The following is a reference document.
[Document 1] Japanese Laid-open Patent Publication No. 2008-182529.